The present invention relates to a method for constructing ideographic characters, e.g. Chinese characters, and comparable graphic designs.
In order to permit machine processing of characters for display by means of a printer or for projection on a video screen, the data for the characters must be contained in a character memory or character generator of the machine. For alphabetic scripts this requires only a small amount of memory space. But the memory space becomes quite a problem when ideographic scripts are to be processed which employ an extensive supply of characters. In the case of Chinese, this would mean that up to 50,000 ideograms would have to be stored in the character generator. Even if the system were limited to the supply of the simplified Chinese telegraph code, about 10,000 ideograms would have to be stored. Moreover, some of these ideograms form complex graphic designs, particularly if the result is to be a display of great accuracy and resolution, and in order to be represented they require a large number of data bits.
To solve this problem, the article "Keyboard Method for Composing Chinese Characters" by E. F. Yhap in IBM Journal of Research Development, January, 1975, pages 60-67, discloses a method according to which the ideographic characters are separated into components and stored, the components preferably being formed by radicals, which are elmentary components of Chinese characters used to form more complex characters. Since the selected components are the basic modules for constructing the ideographic characters, a large supply of characters can be contained in a character generator designed in this way involving a comparatively small number of stored components.
However, the read-out of the ideograms by way of a keyboard, as disclosed in this publication, is a complicated process which requires expensive training of the operator and high concentration during work. Each ideographic character requires the actuation of a varying number of keys, which can be quite large, depending on its complexity, so as to assemble the individual components, define their respective position within the area occupied by the ideographic character and their respective size. In order to make the correct construction of each ideographic character controllable, a single character display is provided on which the step-by-step assembly can be monitored.
To simplify operation of the construction of ideograms by machine, European Patent Application No. 0,009,662, published Apr. 16th, 1980, proposes to select the character components in such a manner that each ideogram can be assembled of only two components which are of identical size in one direction. Two sets of data are stored of which one contains position information for the components within the different ideograms. A playback instruction for a certain ideogram has the result that the two associated components are taken from the first set of data and the position information is taken from the second set of data and the ideogram is composed in a character raster memory.
Although this solution simplifies the operating function, the requirement for memory space is again very large. Since each ideogram must be formed of only two components, most of the components are still very complex and each one of the components can be used only for very few ideograms. Therefore, very many components must be stored and the set of position information data to be stored also is very large.